/* ============================================================
   ToolKit Hub — Design System
   Youthful Enterprise Style  (Indigo + Teal + Glassmorphism)
   ============================================================ */

:root {
  /* Brand */
  --primary-500: #6366f1;
  --primary-600: #4f46e5;
  --primary-700: #4338ca;
  --accent-teal:  #14b8a6;
  --accent-pink:  #ec4899;
  --accent-amber: #f59e0b;

  /* Neutral */
  --bg-body:   #f8fafc;
  --bg-card:   #ffffff;
  --bg-glass:  rgba(255,255,255,0.72);
  --border:    #e2e8f0;
  --border-sub:#cbd5e1;
  --text-main: #1e293b;
  --text-muted:#64748b;
  --text-light:#94a3b8;

  /* Functional */
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 22px;
  --radius-xl: 32px;
  --shadow-sm: 0 1px 2px rgba(15,23,42,0.04);
  --shadow-md: 0 8px 24px rgba(15,23,42,0.07);
  --shadow-lg: 0 20px 50px rgba(15,23,42,0.10);
  --transition: 0.22s cubic-bezier(0.4,0,0.2,1);

  /* Sidebar */
  --sidebar-w: 260px;
  --header-h: 68px;
}

* { box-sizing:border-box; margin:0; padding:0; }
html { scroll-behavior:smooth; }
body {
  font-family: "PingFang SC","Microsoft YaHei","Helvetica Neue",Arial,sans-serif;
  background: var(--bg-body);
  color: var(--text-main);
  line-height:1.55;
  min-height:100vh;
  -webkit-font-smoothing:antialiased;
}
a { color:inherit; text-decoration:none; }
ul { list-style:none; }
button { cursor:pointer; border:none; background:none; font-family:inherit; }
input, textarea { font-family:inherit; outline:none; }
img { max-width:100%; display:block; }

/* Scrollbar */
::-webkit-scrollbar { width:6px; height:6px; }
::-webkit-scrollbar-thumb { background:#cbd5e1; border-radius:3px; }
::-webkit-scrollbar-track { background:transparent; }

/* ============================================================
   Layout
   ============================================================ */
.app-shell {
  display:flex;
  min-height:100vh;
}
.sidebar {
  width:var(--sidebar-w);
  position:fixed;
  inset:0 auto 0 0;
  background:linear-gradient(180deg, #fff 0%, #f8fafc 100%);
  border-right:1px solid var(--border);
  display:flex;
  flex-direction:column;
  z-index:50;
  padding:24px 16px;
}
.main-area {
  flex:1;
  margin-left:var(--sidebar-w);
  min-height:100vh;
  display:flex;
  flex-direction:column;
}
.header {
  height:var(--header-h);
  background:rgba(248,250,252,0.92);
  backdrop-filter:blur(12px);
  -webkit-backdrop-filter:blur(12px);
  border-bottom:1px solid var(--border);
  position:sticky;
  top:0;
  z-index:40;
  display:flex;
  align-items:center;
  justify-content:space-between;
  padding:0 32px;
}
.content {
  flex:1;
  padding:28px 32px 48px;
  max-width:1400px;
}

/* ============================================================
   Sidebar Branding
   ============================================================ */
.brand {
  display:flex; align-items:center; gap:12px; padding:0 8px; margin-bottom:32px;
}
.brand-logo {
  width:42px; height:42px; border-radius:12px;
  background:linear-gradient(135deg,var(--primary-500),var(--accent-teal));
  display:flex; align-items:center; justify-content:center;
  color:#fff; font-size:20px; font-weight:700;
  box-shadow:0 4px 14px rgba(99,102,241,0.35);
}
.brand-text h1 {
  font-size:18px; font-weight:700; letter-spacing:-0.3px;
  background:linear-gradient(135deg,var(--primary-600),var(--accent-teal));
  -webkit-background-clip:text; -webkit-text-fill-color:transparent;
}
.brand-text span {
  font-size:11px; color:var(--text-light); font-weight:500; letter-spacing:0.5px;
}

/* Nav */
.nav-title {
  font-size:10px; text-transform:uppercase; letter-spacing:1.2px;
  color:var(--text-light); font-weight:600; padding:0 8px; margin:8px 0 10px;
}
.nav-list li a {
  display:flex; align-items:center; gap:10px;
  padding:9px 12px; border-radius:var(--radius-sm);
  color:var(--text-muted); font-size:14px; font-weight:500;
  transition:background var(--transition), color var(--transition), transform var(--transition);
  margin-bottom:2px;
}
.nav-list li a:hover, .nav-list li a.active {
  background:rgba(99,102,241,0.08);
  color:var(--primary-600);
  transform:translateX(2px);
}
.nav-list li a svg { width:18px; height:18px; opacity:0.7; }
.nav-list li a.active svg, .nav-list li a:hover svg { opacity:1; }

/* ============================================================
   Header
   ============================================================ */
.search-box {
  position:relative; width:380px;
}
.search-box input {
  width:100%; height:42px; padding:0 42px 0 16px;
  border:1px solid var(--border); border-radius:var(--radius-md);
  background:var(--bg-card); font-size:14px; color:var(--text-main);
  transition:border var(--transition), box-shadow var(--transition);
}
.search-box input:focus {
  border-color:var(--primary-500);
  box-shadow:0 0 0 4px rgba(99,102,241,0.10);
}
.search-box .search-icon {
  position:absolute; right:14px; top:50%; transform:translateY(-50%);
  color:var(--text-light); pointer-events:none;
}
.header-actions { display:flex; align-items:center; gap:12px; }
.btn-icon {
  width:38px; height:38px; border-radius:10px;
  display:flex; align-items:center; justify-content:center;
  color:var(--text-muted); background:var(--bg-card);
  border:1px solid var(--border);
  transition:all var(--transition);
}
.btn-icon:hover { color:var(--primary-600); border-color:var(--primary-500); }

/* ============================================================
   Hero Banner
   ============================================================ */
.hero {
  background:linear-gradient(135deg, rgba(99,102,241,0.08), rgba(20,184,166,0.06));
  border:1px solid rgba(99,102,241,0.12);
  border-radius:var(--radius-lg);
  padding:36px 32px;
  margin-bottom:32px;
  position:relative; overflow:hidden;
}
.hero::before {
  content:""; position:absolute; right:-60px; top:-60px; width:280px; height:280px;
  background:radial-gradient(circle, rgba(99,102,241,0.18) 0%, transparent 70%);
  border-radius:50%; pointer-events:none;
}
.hero h2 {
  font-size:28px; font-weight:800; letter-spacing:-0.5px; margin-bottom:8px;
  color:var(--text-main);
}
.hero p { font-size:15px; color:var(--text-muted); max-width:520px; }
.hero .hero-tags { display:flex; gap:8px; margin-top:16px; flex-wrap:wrap; }
.tag {
  padding:5px 12px; border-radius:20px; font-size:12px; font-weight:600;
  background:rgba(99,102,241,0.10); color:var(--primary-600);
}

/* ============================================================
   Section Title
   ============================================================ */
.section-header {
  display:flex; align-items:center; justify-content:space-between;
  margin-bottom:18px;
}
.section-title {
  font-size:18px; font-weight:700; display:flex; align-items:center; gap:8px;
}
.section-title .dot {
  width:8px; height:8px; border-radius:50%;
  background:var(--primary-500); box-shadow:0 0 0 4px rgba(99,102,241,0.20);
}
.view-all {
  font-size:13px; font-weight:600; color:var(--primary-600);
  display:flex; align-items:center; gap:4px;
  transition:gap var(--transition);
}
.view-all:hover { gap:8px; }

/* ============================================================
   Tool Cards Grid
   ============================================================ */
.tools-grid {
  display:grid;
  grid-template-columns:repeat(auto-fill, minmax(240px, 1fr));
  gap:20px; margin-bottom:36px;
}
.tool-card {
  background:var(--bg-card);
  border:1px solid var(--border);
  border-radius:var(--radius-md);
  padding:22px;
  position:relative;
  overflow:hidden;
  transition:transform var(--transition), box-shadow var(--transition), border-color var(--transition);
  cursor:pointer;
}
.tool-card::after {
  content:""; position:absolute; left:0; top:0; bottom:0; width:4px;
  background:var(--card-accent, var(--primary-500));
  opacity:0; transition:opacity var(--transition);
}
.tool-card:hover::after { opacity:1; }
.tool-card:hover {
  transform:translateY(-4px);
  box-shadow:var(--shadow-lg);
  border-color:var(--border-sub);
}
.tool-card .card-icon {
  width:44px; height:44px; border-radius:12px;
  display:flex; align-items:center; justify-content:center;
  font-size:20px; margin-bottom:14px;
  background:rgba(99,102,241,0.08); color:var(--primary-600);
  transition:transform var(--transition);
}
.tool-card:hover .card-icon { transform:scale(1.08) rotate(-3deg); }
.tool-card h3 {
  font-size:15px; font-weight:700; margin-bottom:6px;
  display:flex; align-items:center; gap:6px;
}
.tool-card p {
  font-size:13px; color:var(--text-muted); line-height:1.5;
  min-height:38px;
}
.tool-card .meta {
  display:flex; align-items:center; gap:8px; margin-top:14px;
  font-size:11px; color:var(--text-light); font-weight:500;
}
.badge {
  padding:2px 8px; border-radius:6px; font-size:10px; font-weight:700;
  letter-spacing:0.4px; text-transform:uppercase;
}
.badge-hot    { background:rgba(245,158,11,0.10); color:#b45309; }
.badge-new    { background:rgba(236,72,153,0.10); color:#be185d; }
.badge-inline { background:rgba(99,102,241,0.08); color:var(--primary-600); }

/* ============================================================
   Featured Strip
   ============================================================ */
.featured-strip {
  display:flex; gap:16px; overflow-x:auto; padding-bottom:6px;
}
.featured-strip::-webkit-scrollbar { height:4px; }
.featured-card {
  flex:0 0 300px; background:var(--bg-card);
  border:1px solid var(--border); border-radius:var(--radius-md);
  padding:24px; position:relative; overflow:hidden;
  transition:all var(--transition); cursor:pointer;
}
.featured-card:hover { transform:translateY(-3px); box-shadow:var(--shadow-lg); }
.featured-card .bg-blob {
  position:absolute; right:-20px; top:-20px; width:120px; height:120px;
  border-radius:50%; opacity:0.12; filter:blur(30px);
  background:var(--blob-color, var(--primary-500));
}
.featured-card .card-icon { margin-bottom:12px; }
.featured-card h3 { font-size:16px; font-weight:700; }
.featured-card p  { font-size:13px; color:var(--text-muted); margin-top:6px; }

/* ============================================================
   Tool Page (Built-in)
   ============================================================ */
.tool-view {
  background:var(--bg-card); border:1px solid var(--border);
  border-radius:var(--radius-lg); padding:28px; min-height:500px;
}
.tool-view-header {
  display:flex; align-items:center; justify-content:space-between;
  margin-bottom:24px; padding-bottom:20px; border-bottom:1px solid var(--border);
}
.tool-view-header h2 { font-size:22px; font-weight:800; }
.tool-desc { color:var(--text-muted); font-size:14px; margin-top:4px; }
.back-btn {
  display:inline-flex; align-items:center; gap:6px;
  font-size:13px; font-weight:600; color:var(--text-muted);
  padding:8px 14px; border-radius:var(--radius-sm);
  border:1px solid var(--border); background:var(--bg-body);
  transition:all var(--transition);
}
.back-btn:hover { color:var(--primary-600); border-color:var(--primary-500); }

/* Form elements inside tools */
.tk-input, .tk-textarea {
  width:100%; padding:12px 16px;
  border:1px solid var(--border); border-radius:var(--radius-md);
  background:var(--bg-body); font-size:14px; color:var(--text-main);
  transition:border var(--transition), box-shadow var(--transition);
}
.tk-input:focus, .tk-textarea:focus {
  border-color:var(--primary-500);
  box-shadow:0 0 0 4px rgba(99,102,241,0.10);
}
.tk-textarea { min-height:200px; resize:vertical; font-family:"JetBrains Mono","SF Mono",Consolas,monospace; }
.tk-label {
  display:block; font-size:13px; font-weight:600; color:var(--text-muted);
  margin-bottom:6px;
}
.tk-row { display:flex; gap:16px; margin-bottom:16px; flex-wrap:wrap; }
.tk-col { flex:1; min-width:200px; }
.tk-btn {
  padding:10px 22px; border-radius:var(--radius-md);
  font-size:14px; font-weight:600; color:#fff;
  background:linear-gradient(135deg,var(--primary-500),var(--primary-600));
  box-shadow:0 4px 14px rgba(99,102,241,0.30);
  transition:all var(--transition);
}
.tk-btn:hover { transform:translateY(-2px); box-shadow:0 6px 20px rgba(99,102,241,0.40); }
.tk-btn.secondary {
  background:var(--bg-body); color:var(--text-main);
  border:1px solid var(--border); box-shadow:none;
}
.tk-btn.secondary:hover { background:var(--border); }

/* ============================================================
   Empty / Loading / Error States
   ============================================================ */
.state-center {
  display:flex; flex-direction:column; align-items:center; justify-content:center;
  padding:80px 24px; text-align:center; color:var(--text-muted);
}
.state-icon {
  width:64px; height:64px; border-radius:50%;
  background:rgba(99,102,241,0.06); display:flex; align-items:center; justify-content:center;
  margin-bottom:16px; color:var(--primary-500);
}
.state-title { font-size:18px; font-weight:700; color:var(--text-main); margin-bottom:6px; }
.state-msg  { font-size:14px; max-width:320px; }
.spinner {
  width:28px; height:28px; border:3px solid var(--border);
  border-top-color:var(--primary-500); border-radius:50%;
  animation:spin 0.8s linear infinite; margin-bottom:16px;
}
@keyframes spin { to { transform:rotate(360deg); } }

/* ============================================================
   Search Overlay
   ============================================================ */
.search-overlay {
  position:fixed; inset:0; background:rgba(15,23,42,0.45);
  backdrop-filter:blur(4px); z-index:100;
  display:none; align-items:flex-start; justify-content:center;
  padding-top:120px;
}
.search-overlay.open { display:flex; }
.search-modal {
  width:560px; max-width:90vw; background:var(--bg-glass);
  backdrop-filter:blur(24px); -webkit-backdrop-filter:blur(24px);
  border:1px solid rgba(255,255,255,0.5); border-radius:var(--radius-lg);
  box-shadow:var(--shadow-lg); overflow:hidden;
}
.search-modal input {
  width:100%; padding:18px 24px; border:none; background:transparent;
  font-size:18px; color:var(--text-main); border-bottom:1px solid var(--border);
}
.search-results { max-height:400px; overflow-y:auto; padding:8px; }
.search-item {
  display:flex; align-items:center; gap:12px; padding:12px 14px;
  border-radius:var(--radius-sm); cursor:pointer;
  transition:background var(--transition);
}
.search-item:hover { background:rgba(99,102,241,0.06); }
.search-item .si-icon { width:36px; height:36px; border-radius:10px;
  display:flex; align-items:center; justify-content:center;
  background:rgba(99,102,241,0.08); color:var(--primary-600); font-size:16px; }
.search-item .si-info { flex:1; }
.search-item .si-name { font-size:14px; font-weight:700; }
.search-item .si-cat { font-size:12px; color:var(--text-light); }
.search-key { font-size:11px; color:var(--text-light); background:var(--bg-body);
  padding:2px 6px; border-radius:4px; border:1px solid var(--border); }

/* ============================================================
   Responsive
   ============================================================ */
@media (max-width:900px) {
  .sidebar { transform:translateX(-100%); transition:transform var(--transition); }
  .sidebar.open { transform:translateX(0); }
  .main-area { margin-left:0; }
  .header { padding:0 16px; }
  .content { padding:20px 16px 40px; }
  .search-box { width:100%; max-width:280px; }
}
@media (max-width:640px) {
  .tools-grid { grid-template-columns:repeat(2, 1fr); gap:12px; }
  .tool-card { padding:16px; }
  .hero { padding:24px 20px; }
  .hero h2 { font-size:22px; }
}
@media (max-width:420px) {
  .tools-grid { grid-template-columns:1fr; }
}